The present disclosure is related to the field of mechanical ventilation. More specifically, the current disclosure is related to the prevention of the delivery of hypoxic gases to a patient.
Known guards against the delivery of hypoxic gases are based upon minimum concentration settings to ensure the addition of adequate fresh gas oxygen to a breathing circuit. Such a minimum concentration setting is maintained with a mechanical or equivalent link between the gas flow settings of the constituent gases of the delivered fresh gas. Such linkages ensure that the resulting mixture of fresh gas maintains a required minimum oxygen concentration.
During some mechanical ventilator operational settings, particularly low flow mechanical ventilator operation, hypoxic gases can still be delivered to a patient, even when known hypoxic guards register that the minimum oxygen concentration for fresh gas flows has been met.